Tried the new battery the t-mobile store gave me and was no better than the original. I bought a new higher powered batter, 1850mAh vs original 1400mAH, and for the first charge it lasted 9 days on standby with some occasional intermittent use. That is a big improvement in total battery life. Got less than 6 days previously.
Not sure about how it will work in Canada where I had 24 hour battery life but am hopeful that will be resolved too.